Iron truss-frame fob bridges



UNITED STATES PATENT OFFICE.

FRANCIS C. LOWTHORP, OF TRENTON, NEW JERSEY.

IRON TRUSS-FRAME FOR BRIDGES, 85o.

Specification of Letters Patent No. 18,548, dated November 3, 1857.

To all whom it may concern:

Be it known that I, F RANoIs C. LOWTHORP, of the city of Trenton, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in the Mode of Constructing Truss- Frames of Iron for Bridges, Roofs, &c.; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings and to the iigures and letters of reference marked thereon.

My invention relates to improvements in iron truss frames, composed of upper and lower chords, vertical posts, diagonals, and counter diagonale and my improvements consist in so constructing and arranging the vertical posts that they may be allowed to vibrate in the upper and lower chords, and that the bottom of the end posts may be allowed to vibrate on the piers or foundations, as fully set forth hereafter.

My improvements have for their object, facility of erecting the frames, avoiding the injurious effects of expansion and contraction on the structure as well as on the piers, and also preventing the effects of sudden shocks from passing trains and other sources.

My improvements are intended for the further purpose of avoiding the planing, fitting and turning, and other expensive work required in the construction of other truss frames.

To enable others skilled in the art of constructing truss-frames for bridges, roofs, &c., to understand more fully the nature of my invention or improvements I will now describe the accompanying drawings, of which- Figure l is a front view of the posts i, h, &c., in which is represented the lateral vertical web or rib, having two holes at c', c', in it for passing the diagonals. Fig. 6 is a cross section of the post z, at a, a, showing the diagonals d, d and c. Fig. 7 is a crosssection of the same post at b, b. Fig. 8 is a front view of a similar post with four openings for the diagonals.

Fig. 2 is a longitudinal elevation of part of a truss-frame, in which is shown, 1st, the vibrating post g, having a rounded top {itting the groove of the cap, e, at t, and a grooved bottom fitting the semi-cylindrical part l, of the base m; 2nd, the posts 7L, 7L, Sac., and the diagonals d, d and c, c passing through the lateral web or rib of the posts at z', z', &c.; the flat part c, o. &c., at the top of the posts is merely intended for ornatogether by the bolts f, f on which the bottom of the vertical posts vibrate.

Fig. 3 shows a front view of the vibrating post g, as also a cross-section of the cap e, &c.

Fig. 9 is a plan of the upper chord, and Fig. 10 a plan of the plates y' y' (lower chords s, s) and of the lower part of the post g, &c.

Fig. 4 is a longitudinal elevation, and Fig. 5, an end view of the cap e.

In Figs. 1, 3, 4, 5 and 9 may be seen the vertical ribs s, s, s, Sac., the top or horizontal plate u, and ribs I), I), the bearing plates q, g, with their projections r, r, of the cap e, and the eye bolt f, passing through the same. The vertical ribs s, s, s, &c., are grooved cross-wise at t to receive the upper ends of the posts.

In Figs. 2, 3 and 10 may be seen the adjusting tie rods le, lc, which must be used to keep the truss-frame in position, when vibrating posts are used at both ends, unless otherwise provided for, the adjustment must be effected by means of the nuts o, 0, &c.

Fig. ll, represents a bridge of two spans with a stationary post F, at the center, and vibrating posts Gr, Gr at each end. The floor may be carried along the bottom chords as at Z, Z, or on the top. In the latter case, slope walls may be carried up at y, and fc, y', by means of which much expense may be saved in masonry and embankment.

It will be readily seen without further description that as the top of the posts fit loosely in the caps (which form a part of the upper chords), so as to vibrate in the same, and at the bottom vibrate on the bolts f, f, the posts may be fitted to their proper position, and in fact the whole structure erected with the greatest facility, and this without that turning, planing, and expensive itting work necessary in the construction of other truss frames. The vibrating posts possess the further advantage of allowing the truss frame to accommodate itself to any undue expansion and contraction or to any sudden shocks caused by passing trains and other causes. By allowing the end posts of the truss frame to vibrate on plates resting on the piers, the latter will also be secured from the effects of sudden shocks, or expansion and contraction.

I do not wish to confine myself to the precise form or size of the parts described.

That I clairn as my invention and desire to secure by Letters Patent is- 1. Arranging and constructing the Vertical posts of iron truss frame girders for bridges and other structures, in relation to the upper and lower chord substantially in the manner herein set forth, in order that the said posts may be allowed to vibrate on the chords for the purpose specified.

2. Allowing the end lposts of truss frame bridges to vibrate on the piers or foundation for the purpose herein set forth.

FRANCIS C. LOVVTHORP.

Witnesses:

DAVID MILLEDGE, CHAS. WHITEHEAD. 

